On 2016/08/17 at 15:24, Dave Young wrote: > Hi, Xunlei, > > On 08/17/16 at 09:50am, Xunlei Pang wrote: >> We have crashk_res only in most cases, but sometimes we have >> crashk_low_res. >> >> For example, on 64-bit x86 systems, when "crashkernel=32M,high" >> combined with "crashkernel=128M,low" is used, so some segments >> may have the chance to be loaded into crashk_low_res area. We >> can't fail it as a memory violation in these cases. >> >> Thus, we add the case to regard the segment as valid if it is >> within crashk_low_res. > crashkernel low is meant for swiotlb, it can be reserved automaticlly > in case there's only crashkernel high specified in cmdline, I'm not > sure it is useful to use crashk_res_low for other purpose and > likely kdump can fail in the case. > > I'm not sure it is really necessary to add this check now, we may > handle it only when there is an actual use case and bug report in > the future.
Thanks for the review. The reason I added this is that crashk_res is allowed to be shrunk, so the segment will surely fall into crashk_low_res if crashk_res was shrunk to be a small range. But yes, this should be a corner case, but seems it does no harm adding this check. Anyway, if you think it's not necessary, let's simply ignore it :-) Regards, Xunlei > > Thanks > Dave >> Signed-off-by: Xunlei Pang <xlp...@redhat.com> >> --- >> kernel/kexec_core.c | 11 ++++++++--- >> 1 file changed, 8 insertions(+), 3 deletions(-) >> >> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c >> index 707d18e..9012a60 100644 >> --- a/kernel/kexec_core.c >> +++ b/kernel/kexec_core.c >> @@ -248,9 +248,14 @@ int sanity_check_segment_list(struct kimage *image) >> mstart = image->segment[i].mem; >> mend = mstart + image->segment[i].memsz - 1; >> /* Ensure we are within the crash kernel limits */ >> - if ((mstart < phys_to_boot_phys(crashk_res.start)) || >> - (mend > phys_to_boot_phys(crashk_res.end))) >> - return -EADDRNOTAVAIL; >> + if ((mstart >= phys_to_boot_phys(crashk_res.start)) && >> + (mend <= phys_to_boot_phys(crashk_res.end))) >> + continue; >> + if ((mstart >= phys_to_boot_phys(crashk_low_res.start)) >> && >> + (mend <= phys_to_boot_phys(crashk_low_res.end))) >> + continue; >> + >> + return -EADDRNOTAVAIL; >> } >> } >> >> -- >> 1.8.3.1 >> > _______________________________________________ > kexec mailing list > ke...@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec
